1. Field of the Invention
The invention relates to an automatic precision apparatus wherein a closed loop is formed between each tool and its respective workpiece so that, should the tool vibrate, the workpiece will vibrate together with the tool, and should the workpiece vibrate, the tool will vibrate together with the workpiece, so that there will not be any vibration of a tool relative to a workpiece or vice versa.
2. Description of the Prior Art
Machines, including a plurality of tools mounted, by means of holding shafts, on a stationary table around a rotary table and angularly spaced therearound, are known in the art. The tools are mounted around and over the rotary table which carries the workpieces. In such tools, the workpieces are moved to different stations, each station containing a different tool, and a different work step is carried out on the workpiece by the different tools at each of the stations.
In such machines, it is common practice to have the means for moving the rotary table mounted underneath the table, on the machine base, while the shafts for carrying the individual tools are supported by a flange-like means extending from the machine base around the rotary table. In such prior art machines, a rotary table is not directly mechanically connected to the tool holding shaft, if the rotary table should vibrate, it will vibrate relative to the tool holding shaft. Accordingly, a workpiece would vibrate relative to the tool working on that workpiece. In the same way, if the tool holding shaft should vibrate, then a tool would vibrate relative to the workpiece on which it is working.
Such relative vibration can cause misalignment as between the working tool and the workpiece so that the precision of such machines deteriorates.
As will be appreciated, all of the above tools will require some indexing means to locate a tool adjacent its workpiece as the tools or workpieces are rotated relative to each other. Such indexing, and especially high precision indexing at high speeds, is very difficult to accomplish.
The indexing problem has been attacked in the prior art, and U.S. Pat. No. 3,552,242, Morgan Jr., et al, issued Jan. 5, 1971, U.S. Pat. No. 2,403,405, Sirola, issued July 2, 1946, U.S. Pat. No. 3,621,736, Stanley, issued Nov. 23, 1971, U.S. Pat. No. 2,471,403, Benes, issued May 31, 1949 and U.S. Pat. No. 2,908,195, Benes, issued Oct. 13, 1959 all relate to turrets for lathes which include indexing devices. The indexing devices in each of the above patents include metal balls which are retained in indentations in plates. In all of the above patents, the balls are also spring biased, and it is always the tool holding plate which is rotated relative to the workpiece.
U.S. Pat. No. 3,699,844, Perminov, issued Oct. 24, 1972, teaches an indexing system which consists of metal balls disposed in seating indentations of parallel plates. The indentations are, of course, disposed in facing surfaces of the plates. In the Perminov patent, the balls are rigidly fixed in the upper plates.
The problem of vibration has also been attacked in the prior art, and U.S. Pat. No. 3,153,953, Edgar, issued Oct. 27, 1974, teaches the use of an aligning bar precision index which acts to dampen vibration in an indexing turret. It is also known in the prior art to move the workpiece retaining means relative to the tools. This is shown in U.S. Pat. No. 1,278,407, Werth, issued Sept. 10, 1918, U.S. Pat. No. 1,499,456, Hartmann, issued July 1, 1924, and U.S. Pat. No. 2,783,688, Gunderson, issued Mar. 5, 1957.